snowy river environmental flows report 2012
TRANSCRIPT
Guillermo Umana
Macquarie University
ENVG267
Snowy River Environmental Flows Report 2012
Table of Contents
1. Introduction
2. Findings
2.1 . Natural and Current Total Flow Volumes
2.2 Seasonal Variability in Flows
2.3 Flood event Frequencies
3. Discussion
4. Recommendations
5. References
Executive Summary
It is clear now, after 10 years of environmental flows down Jindabyne dam, that the
progress in regaining environmental stability in the Snowy River has been little. This report
draws on previous monitoring reports from different sources, including the Snowy River
Scientific Committee, The Snowy Water Inquiry and Snowy River Alliance, to compare the
pre and post Hydroelectric Scheme environmental state of the Snowy River with its current
state. It can be argued that the main reasons for lack of environmental flow target-meeting
are droughts and the water entitlements payed by the government such as the Mowamba
Borrowing account. This report concludes that droughts and environmental variability will
continue as the effects of climate change become stronger in South-Western Australia, so
they should not be an excuse not to release adequate environmental flows into the Snowy
River. Political will should be enhanced by further transparency in the monitoring and
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increasing role of the now inactive Snowy Scientific Committee. The government should
repay all borrowings as soon as possible and make sure that future flows mimic seasonal
flows in a more adequate way. Today sedimentation continues to be a problem, as well as
invasive vegetation and poor habitat for native species. It is recommended that a new
Snowy Inquiry takes place to create new targets that better reflect the current situation of
the river and the effects of climate change.
1. Introduction
The Snowy Mountains Scheme diverts the water of 12 rivers and 71 creeks in the Snowy
Mountain region to generate hydro-electric power and provide water for irrigation of lands
to the West of the Snowy River (Smith, 2000). The economic and social importance of the
Scheme contrasts with the environmental degradation that diverting the waters generate.
Since the begging of the Scheme’s operations, 99% of the Snowy River’s natural flow below
Jindabyne Dam has been diverted, producing sedimentation, poor habitat quality for native
species and lack of water mixing among other problems (Smith, 2000).
Map 1. Illustrative Map of the Lake Jindabyne Area (Australian Geographic, 2011)
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In 1997 with the Snowy Hydro Corporation Act, the governments of New South Wales,
Victoria and the Commonwealth created the Snowy River Inquiry, a project to gather
community and expert opinions about the future of the Snowy River. The Inquiry provided
the government with a series of composite options to generate a positive impact on the
Snowy River. In 2002, a historic agreement between NSW, Victoria and the Commonwealth
was signed to return 21% of the Snowy’s natural flow by 2012 (ADE, 2010). This meant that
by 2012, more than 120 GL of water should have been flow down the Snowy (Snowy
Scientific Committee, 2008). In reality the flows did not surpass 38Gl a year between 2005
and 2009.
Map 1 (above) shows the Snowy River at Jindabyne Dam, which is the dam that was chosen
in 2002 to release the environmental flow. The map also shows the Mowamba River, which
provided the Snowy with environmental flows for a period of time from 2002 to 2005. These
flows had to be re-payed to Snowy Hydro Ltd by the government(s) through the Mowamba
Borrowing Account, which meant that after 2006, the environmental flows to the Snowy
were reduced to allocate the water to other Snowy Hydro commitments (ADE, 2010). This
reduction was also reinforced by the droughts that occurred during the first decade of the
21st century. Anyhow, La Niña events during 2010-2011 have meant that more water is
being allocated to the environmental flows in recent years.
This report argues that the environmental flow scheme should avoid being dependant on
climate change to deliver appropriate flows to the river. A review of the current procedures
should be made to adapt the flows to a less climate-dependant scheme. Also, monitoring
transparency and political will should be enhanced to make the environmental flows
become a regular activity, with constant improvements.
2. Findings
2.1 Natural and Current Total Flow Volumes
The Snowy Water Scheme requires that at least 2,088 GL of water are diverted to the
Murray and Murrumbidgee systems each year, from which more than half comes from the
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Snowy catchment (Smith, 2000). Table A provides information on natural and actual flows of
the Murray, Murrumbidgee and Snowy and the amount of households dependant on those
rivers.
Table A. Key Statistics for the three main Snowy River Scheme River (Smith, 2000: 9)
It is clear from the table that percentage of difference between the natural flow of the
Snowy and its current flow is much greater than the one for the other 2 rivers. Although
tributary rivers provide the Snowy with extra water below Jindabyne, the flow at its mouth
is half of what it would be at natural flow.
On the other hand the number of households benefited directly by the Murray and
Murrumbidgee is more than 6 times the one for the Snowy River. Smith (2000) points out
that the irrigated lands of the Murrumbidgee and Murray support agricultural production
over $750 million a year with water from the Scheme. The Scheme also produces 38% of
Australia’s hydroelectric power (Erskine, 1999A). The economic importance of the water
diversion is obvious, but the importance to recuperate the Snowy River is also evident. Both
interests can be met more accurately if Climate Change and transparency are enhanced, as
argued below.
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2.2 Seasonal variability in Flows
The reduction of flows in the Snowy River cannot be seen as a simple reduction of water
volume. The impact on native species, water variability, flow duration and frequency of
floods are some of the recorded effects of the 30 years of constant flows at 1% of the
natural levels (Erskine, 1999A). Figure 1 (below) shows a comparison of the flows of the
Snowy River below Jindabyne Dam and Dalgety. Both comparisons not only show a massive
reduction of flows but also a complete lack of seasonality, which is essential for the health
of native species, the movement of sediments downstream and water mixing. Degradation
of the river environment downstream of Jindabyne is in a great extent caused by the lack of
seasonality.
Figure 1. Changes in mean monthly discharge pre-and-post-SMHS (Erskine et al., 1991A: 9)
It can be argued that stronger peak flow events are needed. Although environmental flows
since 2002 have aimed to input seasonal variation, the effects have been minimal. Since
2010, peak flows have been increased in days and volume (as shown in the discussion
below) but furthering peak flows in spring are needed to fully clear the sedimentation
problems, especially at the mouth of the river and provide native species with regular
seasonal changes.
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2.3. Flood Event Frequencies
Figure 2. Pre-and post- Jindabyne Dam annual flow volumes at Dalgety (Rose & Bevitt,
2003: 14)
Figure 2 (above) shows the impact of the Scheme in flood variability and baseline flows in
the Snowy River. While the average flows prior to 1966 were above 1000000 ML a year, the
average flows from 1966 to 1995 were well below 200000 ML a year. Most importantly, the
variability of floods was very high prior to the scheme, with peak years reaching 25000000
ML. During the operation of the scheme, the Snowy has not seen annual flows above
500000 ML.
The environmental flows up to now have not been able to fully address the sedimentation
and poor river habitats generated by low flows. Even after the first environmental flows in
2002, the mouth of the river has been having entrance closures (see Picture 1). For example
on 31st of December 2006, the entrance closed, and was manually opened on 4th of March
2007, only to close again on the 9th of April (Wheeler et al, 2009). A factor that has made
environmental flows ineffective is a reduction of snow melting in the snowy mountains
because of less snow precipitation. Lower volumes from the tributaries of the Snowy mean
weaker discharges to the ocean. Floods with a peak discharge size at least four times greater
than the mean annual flood are important in mobilising sediment (Rose & bevitt, 2003). An
adjustment of the environmental flows is needed to address the impacts of less and less
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snow in the Snowy Mountains and less and less water from tributaries to support
environmental flows.
Picture 1. Google earth View of the end of the Snowy River
(https://maps.google.com.au/maps?
q=marlo&ll=37.799069,148.554811&spn=0.035538,0.084543&hnear=Marlo+Victoria&gl=au&t=h&z=14)
3. Discussion
The reality of the environmental flow program is that the targets created in 2002 will not be
met. Figure 3 shows the comparison between real and target GL of water per year released
to the Snowy River. It is possible to see that between 2004 and 2005 and between 2007 and
2008 the droughts forced a decrease of the flow down the river to levels similar to 1998-
1999 ones.
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Figure 3. Comparison of Target (SWIOID 2002) versus Actual Volumes in the Snowy River,
GS 222026 (Dalgety) (Snowy Scientific Committee, 2008: 6)
According to the Department of Primary Industries, the reasons for the unavailability to
meet the targets are: The repayment of the initial releases to the Snowy River which are
part of the Mowamba Borrowing Account and the drought conditions since 2002.
According to the report by the Snowy Scientific Committee (2009), Snowy Hydro Ltd had
followed the requirements of the Water Consultation Liaison Committee with no input of
the SSC. The lack of target-meeting since 2002 has been accompanied by a lack of
transparency in the monitoring. In May 2011 the Committee’s first three-year term expired
and to date (Oct 2011) it has still not been re-established (Snowy Alliance, 2011).
Consequently there has been no Snowy Scientific Committee to oversight the October 2011
big spring releases or prepare release recommendations for the 2012-13 Water year to the
Snowy, which must be completed by January (Snowy Water Alliance, 2011).
Wheeler (2009) explains a significant reduction in rainfall and snowfall have been recorded
since 1950, and the trend will continue, which makes it evident that meeting targets for
environmental flows will become harder each year. Variability in climate will increase as
well, with years of high rainfall such as 2011-2012 and years of very little rainfall such as
2008.
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Table B shows the peak flow rates of 2010, 2011, 2012. It can be seen that the amount of
water released for the peak flows for 2011 and 2012 are much higher than the one in 2010.
La Niña events during 2010-2011 mean less pressure to divert water to the Murray and
Murrumbidgee. On the other hand, El Niño events are expected for the coming years, and
the way the Scheme will cope with the possible droughts will define future environmental
flows.
Table B. Peak flow Rates for 2010, 2011 and the expected values for 2012 (Department of
Primary Industries, 2012)
Inconsistency in the flows is not an effective way to maintain the river channel in the long
run, so alternative ways of maintaining the downstream areas of the Snowy without being
affected by climate change variability should be generated. Due to high rainfall and
significant inflows into Lake Jindabyne in early 2012, a total of 80 GLs of water was released
into the Snowy River system below Jindabyne Dam. This is a positive event, but what will be
of the environmental flows during the possible El Niño events of 2012-2013?
4. Recommendations
There must be a re-evaluation of the environmental flow scheme and a new set of more
transparent targets that take into account the realities of Climate Change. In 2009 the
Snowy Scientific committee recommended that a persistent but variable base flow
throughout the year; with a peak flow of 870 ML d-1, lasting 1-2 days released in January;
and again in February would minimise the likelihood of poor water quality in pools and
consequent stress on in-stream fauna. The future of the Snowy River environmental flows
depends on the ability of the government in partnership with Snowy Hydro to use the water
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in the most efficient way. It has been seen that climate change will make it harder and
harder to avoid the pressures that the agricultural lands around the Murray and
Murrumbidgee will generate on the Snowy. Reduction of the water diverted to these areas
will be a task that will involve new agricultural technologies, relocation of households away
from these vulnerable areas and more controls over agricultural use of water in these areas.
The complex nature of the Scheme makes it difficult to make recommendations that avoid
complex regional strategies. As for the next 10 years, the governments of NSW, Victoria and
Australia should show more transparency in the functioning of the environmental flows and
the Independent Snowy Scientific Committee must be immediately be re-established to
ensure transparency of procedures (Snowy River Alliance, 2011). The Mowamba Borrowing
Account should be reviewed. It is clear that extra cuts on the environmental flows down
Jindabyne to repay borrowings will make the existing flows inefficient to combat
sedimentation and loss of habitat. A new Snowy Water Inquiry could be a possibility to find
other ways of compensating Snowy Hydro ltd for the water that will be put into the
environmental flows, without having to reduce the flows to the levels seen in 2004-2008.
5. References
Australian Department of the Environment, (2010), Snowy River Environmental Flows, <
http://www.youtube.com/watch?v=jcDHc63Aehw>, accessed 4 September 2012.
Australian Geographic, (2011), Snowy River Map, BYAG CARTOGRAPHY, MAY-19-2011,
<http://www.australiangeographic.com.au/journal/snowy-river-map.htm>, accessed 4
September 2012.
Climate Change In Australia, (2012), ‘Regional climate change projections TECHNICAL
REPORT’, Chapter 5,
<http://www.climatechangeinaustralia.gov.au/documents/resources/TR_Web_Ch5i.pdf>,
accessed 4 September 2012.
Department of the Environment, (2012), ‘Rising river alert Snowy River below Jindabyne
Dam’, Media Release, 23 August 2012.
Department of Primary Industries, (2012), ‘Office of Water Website’, <
http://www.water.nsw.gov.au/Water-management/Water-recovery/Snowy-Initiative/
Snowy-initiative/default.aspx>, accessed 4 September 2012.
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Erskine, W.D., Terrazzolo, N. and Warner, R.F, (1999A), ‘River rehabilitation from the
hydrogeomorphic impacts of a large hydro-electric power project: Snowy River, Australia.’
Regulated Rivers: Research and Management, 15: 3-24.
Erskine, W.D., Turner, L.M., Terrazzolo, N. and Warner, R.F, (1999B), ‘Recovery of the Snowy
River: politics and rehabilitation’. Australian Geographical Studies, 37(3): 330-36.
Rose, T. A. and Bevitt, R., (2003), ‘Snowy River Benchmarking and Environmental Flow
Response Monitoring Project: Summary Progress Report on available data from 1999—
2001’, Environment Australia. DIPNR, Cooma NSW,
<http://www.environment.gov.au/water/publications/environmental/rivers/nrhp/
snowy.html>, accessed 4 September 2012.
Smith, S, (2000), ‘The Future of the Snowy River’, Briefing Paper 2/2000, NSW Parliamentary
research Service,
<
http://www.parliament.nsw.gov.au/prod/parlment/publications.nsf/0/30970BFB572FC564C
A256ECF000707D3/$File/02-00.pdf>, accessed 5 September 2012,.
Snowy Scientific Committee, (2008), ‘Adequacy of environmental flows to the Snowy River
Report SSC_1’, Snowy Scientific Committee for the Water Administration Ministerial
Corporation, Canberra, October 2008.
Snowy River Alliance, (2011) ‘Fact Sheet 2011’,
<http://www.snowyriveralliance.com.au/facts.html>, accessed 4 September 2012.
Snowy Scientific Committee (2009), ‘Environmental Releases from Jindabyne Dam:
Recommendations for 2009-2010’. Report SSC_2. Prepared for the NSW Water
Administration Ministerial Corporation. Canberra. June 2009.
Wheeler P; Nguyen T; Peterson J; Gordon-Brown L (2009), ‘Morphological Change at the
Snowy River Ocean Entrance, Victoria, Australia (1851-2008)’, Monash University, Australia,
Online Publication Date: 01 March 2009
Wolfenden, B, Brooks A, Williams, S, (2008), ‘Snowy Flow Response Monitoring and
Modelling The potential drift-barrier effect of Mowamba Weir’, Office of water, NSW,
Australia.
Snowy Water Inquiry, (1998), ‘Final Report: submitted to the governments of NSW and
Victoria’, Snowy Water Inquiry, Sydney,
<
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http://www.parliament.nsw.gov.au/prod/PARLMENT/Committee.nsf/0/93FF46746ED75CFB
CA2571A3001A7>, accessed 4 September, 2012.
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